Engine cylinder



H. ALFARO ENGINE CYLINDER Feb. 14, 1939.

Filed Oct. 15, 1935 2 Sheets-Sheet 1 INVENTOR Heraclio Alf'aro BY vuo 9Mc.

ATTORNEYS Feb. 14, 1939.

H. ALFARO Y ENGINE CYLINDER Filed Oct. 15, 1935 2 Sheets-Sheet 2 YIIIIIIIIIIIIIIIII/ INVENTOR Hera clio A Z faro ATTORNEYS Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to the cooling of internal combustion engines by means of liquid circulation and particularly to the liquid cooling of barrel or crankless engines. The invention is primarily applicable to engines of the two-cycle variety but can be used in other engines having ported cylinders.

It is the aim of this invention to provide a simple and light weight construction for the cylinders of liquid cooled engines and to provide a simple and efficient liquid circulating means which will permit of a light weight and compact cylinder assembly as is desirable in engines for aircraft, automobiles and the like.

The main objects of the invention are to provide an engine of very simple and compact construction,.to effect economies in the manufacture of the engine, and to provide an efficient cooling system.

Other advantages will be apparent to anyone skilled in the art to which this invention appertains.

Reference should be had to the accompanying drawings forming a part of this specification in which:

Figure 1 shows, in longitudinal section, a cylinder of an engine embodying the invention;

Fig. 2 is a fragmentary section taken on the line indicated at 2-2 in Fig. 1;

Fig. 3 is a section through a plurality of the cylinders taken on the line indicated at 3-3 in Fi 1;

Fig. 4 is a fragmentary sectional view showing a slightly different connection between the liquid passage of the casing and the water jacket;

Fig. 5 shows a modified cylinder construction;

Fig. 6 shows another form of connection between the liquid passage of the casing and the water jacket;

Fig. '7 is a fragmentary View showing a modified jacket inlet.

To simplify the construction of liquid cooled engines, I prefer to build the cylinders in separate units. This form of construction is shown in the accompanying drawings wherein the cylinder is indicated by the reference numeral l, and the front and rear casing members in which the ends of the cylinders are mounted are indicated by the reference numerals 2 and 3.

The present invention is particularly applicable to engines of the barrel type in which parallel cylinders are spaced circumferentially about a cen.. tral shaft la: as shown in Fig. 3, each cylinder having opposed pistons lb, fragmentary portions of which are shown in Fig. 1. The cylinders,

which are of identical construction, have their front and rear ends mounted in front and rear casing members 2 and 3 as shown in Fig. 1. Each cylinder has external circumferential flanges 4 and 5 which are spaced inwardly from the for- 5 Ward and rear ends of the cylinders, and the end portions of the cylinders outwardly of the flanges 4 and 5 are seated in openings formed in the casing members 2 and 3 with the flanges 4 and 5 bearing against the inner faces of the casing 10 members 2 and 3. The body of the cylinder I is preferably made of a malleable ferrous metal which is machined to form one or both of the flanges 4 and 5 and to provide external bosses at the ports and other openings. 15

The cylinder is provided with air intake ports 7 adjacent one end outwardly ofthe flange 5 and with exhaust ports 8 intermediate the flanges and may be provided with additional ports 9 between the exhaust ports 8 and the flange 4 of the cylin- 0 der to circulate air through the pistons.

The sheet metal jacket ID is seated at its ends on shoulders II at the inner sides of the flanges 4 and 5. Intermediate its ends the jacket is provided with openings to accommodate the ports 25 8 and 9 and also suitable fuel injection and ignition devices which may be mounted in openings l3a in the cylinder l. The ports 9 are provided with bosses l2, the openings Bar for fuel injection and ignition devices with bosses l3, and at the 30 exhaust ports 8 there is a continuous boss l4 forming bridges between the ports. The jacket 10 seats upon the bosses l2. l3, and M as well as upon the shoulders H.

The cylinders I are preferably made of steel 35 and the jackets It may also be made of steel. The sheet steel jacket I0 is preferably secured to the cylinder I by fusing copper or other suitable metal between the contiguous surfaces of the cylinder and jacket. This can be done in an atmosphere 40 of hydrogen or other gas that will prevent oxidation or deterioration under heat of the surfaces of parts being joined.

The casing members 2 and 3 in which the cylinders are mounted are preferably provided with 45 passages for liquid which communicate with the cylinder cooling chambers. The casing member 2 is provided with an annular chamber 15 surrounding the end of the cylinder and this chamber communicates with openings in the flange 50 4 which are disposed inwardly of the shoulder If and communicate with the cylinder cooling chamber within the jacket II]. The chamber l5 communicates with a passage I! in the casing member through which the liquid may pass to a 55 radiator or other suitable liquid cooling device. In order to prevent leakage from the chamber 15, a gasket 18 may be placed between the flange 4 and casing member 2 outwardly of the openings l6 and a second gasket 19 may be placed between a short annular rib 20 on the cylinder and an overhanging shoulder 2| on the casing member 2.

The casing member 3 is provided with an annular chamber 22 around the air intake ports 7 which may communicate with a suitable source of air under pressure and, inwardly of the chamber 22 the casing member 3 is provided with a second annular chamber 23 which opens to apassage 24 to which liquid may be returned from a radiator or other cooling device. The chamber 23 communicates with openings 25 in the flange.

5 through which the liquid may pass from the chamber 23 to the cylinder cooling chamber. To prevent leakage of liquid from the chamber 23, a gasket 26 may be placed between the flange 5' and the casing member 3 outwardly of the openings 25, and a second gasket 2'! may be placed between the inner wall of the chamber 23, and a short rib on the cylinder.

In order to prevent overheating of the thickened wall adjacent the exhaust ports, holes 28 extend axially through the bridges between the exhaust ports 8. The holes 28 may be cored-in the casting. but I prefer to form them by drilling through the flange 4, forming the holes 28 in alinement with openings IS in the flange 4 as shown in Fig. 1. One of the bridges may be opposite one of the bosses l2, in which case it will be necessary to drill through the boss l2 and then close the openings formed in boss 12 with suitable plugs 29- as shown in Fig. 1.

It is highly desirable to provide exhaust connections from which heat may be readily dissipated.

As shown in Fig. 2, thin walled ducts 30 are secured in the exhaust openings 3 to convey the exhaust gases to a suitable manifold. These ducts are preferably permanently secured in the exhaust openings by brazing and are made of any steel or other alloy which is resistant to corrosion, and has good brazing and heat-conducting characteristics.

The ports 9 are provided for the air cooling of pistons and permit passage of air from the central space about which the cylinders are grouped into the inner port 9 through lateral passages formed in a pistonto the outer port 9 as shown diagrammatically in Fig. 3.

As shown in Fig. 3, the spaces between adjacent cylinders i may be blocked by partition members 3| so that a central chamber is provided into which air may be delivered under pressure and from which the air may pass through the ports 9 and pistons.

In Fig. 4 of the drawings, a slightly modified construction is illustrated in which the piston cooling ports are omitted and the exhaust ports are placed closer to the end of the cylinder.

The cylinder la is, in this case, mounted in an end casing member 2a and has a flange 4a which bears against the inner face of the member 2a. The end of the cylinder projects beyond the outer face of the casing member and is threaded to receive a nut 32 which clamps the casing member against the flange 4a. The casing member 2a is provided with an annular cored chamber I5a and an outlet passage lla.

At the inner edge of its cylinder receiving opening, the casing member 2a is beveled to provide an annular space 34 communicating with openings I6a in the flange 4a. Passages 35 are drilled from the beveled surface to the interior of the chamber |5a to establish communication between the chamber l5a, passages 35, space 34 and openings 16a, to the cylinder cooling chamber.

In Fig. 5 of the drawings, the cylinder 2b is provided with an integral jacket. The end of the cylinder seats in a casing member 41) and a passage 36 to the cylinder cooling chamber is formed in the cylinder itself. The bridges between the exhaust ports are provided with openings 31 for passage of liquid, which are preferably formed by drilling from the end of the cylinder wall, the openings formed in the end of the cylinder being closed by suitable plugs 38.

Fig. 6 of the drawings shows a cylinder 10 clamped to a casing member 20 by means of a nut 320. The casing member 2c has an annular chamber 39, an outlet passage 40 leading from the chamber 39'and an opening 4| from the chamber 39 to the inner side of the casing member, said opening 4| being spaced outwardly from the cylinder. A short tube 42 integrally united to the jacket I00 has an outer end adapted to register with the opening 4| and is provided with a flange 43 adapted to seat upon a gasket 44 which extends around the opening 4|. When the cylinder is clamped to the casing member lo, the flange 43 is pressed against the gasket 44, making a fluidtight seal.

In Fig. '7 of the drawings, there is shown a modified construction in which the cooling liquid may be delivered to the cylinder cooling chamber directly through the sheet metal jacket.

The jacket Hid is here provided with a short nipple or tubular extension 45 which is integrally united to the jacket and adapted to be joined to a suitable conduit extending to the radiator.

It will be seen that the present invention provides an advantageous construction permitting cylinders of adequate strength to be made of very light weight, providing effective cooling with a minimum wall thickness and providing a construction which is-simple and inexpensive to manufacture.

Furthermore, it is to be understood that the particular form of apparatus shown and described, and the particular procedure set forth, are presented for purposes of explanation and illustration and that various modifications of. said apparatus and procedure can be made without departing from my invention as defined in the appended claims.

What I claim is:

1. In liquid cooled internal combustion engines, a cylinder, a cylinder supporting casing member having an opening in which an end of the cylinder fits, a jacket surrounding the wall of said cylinder, a flange near the. end of the cylinder for engagement with said casing, a duct for the cool.- ing liquid in said casing member extending to the portions thereof surrounding the cylinder, and

passages through said flange connecting the spacebetween the cylinder and jacketto said duct.

2. In liquid cooled internal combustion engines,

an elastic gasket between said flange and said wall.

3. In liquid cooled internal combustion engines, a cylinder, a supporting casing, a jacket surrounding said cylinder, an end of said cylinder being arranged for engagement with its supporting casing, a duct for the cooling liquid in the supporting casing, another duct connected to the jacket for engagement with the first duct in the supporting casing, and an elastic gasket at the point of engagement of the two mentioned ducts.

4. In liquid cooled internal combustion engines of the type having two opposed pistons per cylinder, a cylinder open at both ends and having a flange spaced inwardly a short distance from each end, a jacket surround ng said cylinder and providing a cooling chamber, cylinder supporting casing members having openings in which the opposite ends of the cylinder fit, chambers in the portion of the casing members surrounding-the cyl nder carrying cooling liquid, and ducts connecting said chambers of the casings with the cooling chamber between the jacket and the cylinder.

5. In liquid cooled internal combustion engines of the type having two opposed pistons per cylinder, a cylinder open at both ends and having a flange spaced inwardly a short distance from each end, a jacket surrounding said cylinder and providing a cooling chamber, cylinder supporting casing members having openings in which the opposite ends of the cylinder fit, chambers in the portion of the casing members surrounding the cylinder carrying cooling liquid, ducts connecting said chambers of the casings with the cooling chamber between the jacket and the cylinder, and elastic gaskets between the casings and the flanges of the cylinder.

6. In internal combustion engines, a cylinder, a jacket surrounding the cylinder, ports in said cylinder, bridges between said ports, drilled passages in the bridges between ports communicating at both ends with the space between the cooling jacket and the cylinder, members spacing the jacket from the cylinder, one of said members having an opening alined with said drilled passage, and a plug in said opening.

7. In liquid cooled internal combustion engines,

a cylinder having inlet and exhaust ports, a cooling jacket surrounding the cylinder built independently and permanently attached to said cylinder, an additional port opening through said cylinder and jacket at one side thereof to permit entry of air for cooling the pistons, and a second additional port in said cylinder and jacket diametrically opposed to the entrance port for the outlet of said cooling air.

8. In multicylinder barrel engines, a central shaft, a plurality of independent cylinders arranged circumferentially about the shaft, casing members in which the ends of said cylinders are supported, said cylinders being provided with jackets for liquid cooling, passages in said casing members, and communicating connections between the jackets of the cylinders and said passages in the said casing members.

9. In liquid cooled internal combustion engines, a cylinder, a jacket surrounding said cylinder, exhaust ports in the cylinder, and a thin walled metal duct leading from each exhaust port, each duct having its end fitting in one of said ports and permanently joined to the cylinder.

10. In a liquid cooled internal combustion engine of the type having two opposed pistons per cylinder, a cylinder open at both ends and provided with spaced concentric walls providing a cooling chamber, cylinder supporting casing members having openings in which the opposite ends of the cylinder fits, and provided in the portions thereof surrounding the cylinder with passages for cooling liquid, said passages in the casing members being in communication with the cylinder cooling chamber whereby cooling liquid may be circulated through the cylinder and casing members.

11. In, a liquid cooled internal combustion engine, a plurality of cylinders, a cooling cylinder surrounding each chamber, a cylinder supporting casing member having openings within which the ends of the cylinders fit, a passage in the portion of said casing around the cylinders arranged to circulate cooling liquid and communicating connections between said cooling chambers and said passage in the casing.

HERACLIO ALFARO.

CERTIFICATE OF CORRECTION.

Patent No. 2,11 .7,186. I February 1h, 1959.

HERACLIO ALFARO. 9 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, second column, lines 59 and L O, claim 11, for the words "cylinder surrounding each chaniber" read chamber surrounding each cylinder; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case" in the Patent Office.

Signed and sealed this LLth day of April,- A. D. 1959.

Henry Van Arsdal e (Seal) Acting Commissioner of Patents. 

